有、无垫片钛网植骨对终板-钛网界面应力分布影响的比较

目的 比较有、无垫片钛网植骨对颈椎前路椎体次全切除减压终板-钛网界面应力分布的影响.方法 利用Ansys 9.0软件的建模功能,建立有、无垫片钛网植骨钢板固定手术模型.分别对模型施加80 N预载荷及1.8 Nm力矩,使其产生轴向压缩、前屈和后伸运动,选取终板.钛网界面7个接触点,提取各个点的von Mises应力,然后进行比较.结果 在各种工况下,有垫片钛网植骨C4下终板-钛网界面(5.43、5.74、6.88)Mpa和C6上终板-钛网界面7个各个接触点的应力(7.61、8.23、9.97)Mpa分别小于无垫片钛网植骨C4下终板-钛网界面(7.46、8.12、10.04)Mpa和C6上终板-钛网界面相应接触点的应力(10.65、11.59、14.27)Mpa.结论 有垫片钛网植骨能够降低终板-钛网界面的应力,避免终板应力的过度集中,从而降低钛网下沉的发生率.     

一种新型植骨重建钛网的三维有限元研究

【摘要】 目的 研究新型植骨重建钛网的生物力学特点及其避免术后沉陷的有效性。 方法 设计并研制了一种新型的植骨重建钛网,以现有钛网为研究对照,建立使用2种钛网的椎体次全切除植骨重建手术的三维有限元模型,施加载荷,模拟术后颈椎活动,分别在屈曲、侧屈及扭转3种工况下施加73.6 N 的预载荷,观察钛网、钢板以及相邻椎体终板的应力分布。 结果 在3种不同工况条件下,使用新型植骨重建钛网较使用现有钛网可使钢板承受应力减低1.48~3.95 MPa（23.5%~41.3%）,钛网承受应力增加0.61~1.13 MPa（12.2%~22.2%）,相邻椎体下终板承受应力降低0.41~1.43 MPa（27.7%~44.9%）,相邻椎体上终板承受应力降低0.91~1.42 MPa（28.0%~38.6%）。结论颈前路椎体次全切除减压术中使用新型钛网进行植骨重建可一定程度上增加手术节段稳定性,降低术后钛网沉陷的可能性。     

一种新型植骨重建钛网的三维有限元研究

目的研究新型植骨重建钛网的生物力学特点及其避免术后沉陷的有效性。方法设计并研制了一种新型的植骨重建钛网,以现有钛网为研究对照,建立使用2种钛网的椎体次全切除植骨重建手术的三维有限元模型,施加载荷,模拟术后颈椎活动,分别在屈曲、侧屈及扭转3种工况下施加73．6N的预载荷,观察钛网、钢板以及相邻椎体终板的应力分布。结果在3种不同工况条件下,使用新型植骨重建钛网较使用现有钛网可使钢板承受应力减低1．48—3．95MPa（23．5％～41．3％）,钛网承受应力增加0．61～1．13MPa（12．2％～22．2％）,相邻椎体下终板承受应力降低0．41～1．43MPa（27．7％～44．9％）,相邻椎体上终板承受应力降低0．91～1．42MPa（28．0％-38．6％）。结论颈前路椎体次全切除减压术中使用新型钛网进行植骨重建可一定程度上增加手术节段稳定性,降低术后钛网沉陷的可能性。     

终板切除对终板-钛网界面应力分布影响的三维有限元分析

目的 采用三维有限元法比较终板切除与否对颈椎椎体次全切除减压终板-钛网界面应力分布的影响.方法 在正常人C4～C7三维有限元模型基础上,模拟颈椎(C5)椎体次全切除减压手术,建立颈椎前路减压、终板保留与不保留两种手术模型.利用Ansys 9.0软件的建模功能建立12 mm直径钛网(无垫片)、颈椎前路钢板以及螺钉模型,分...     

颈前路钛网植骨融合术后钛网沉陷的原因探讨

目的：探讨颈前路钛网植骨融合术后钛网发生沉陷的原因及其对临床疗效的影响，并提出相应对策。方法：回顾性分析在我院行颈前路钛网植骨融合术的各类颈椎疾患患者179例，观察患者骨密度、钛网修剪及放置情况、终板处理情况、钢板类型、植骨及椎体撑开情况等。采用日本骨科学会（JOA）评分法评价神经功能的变化。结果：有17例患者发生钛网沉陷，沉陷的原因主要为骨密度下降、钛网修剪放置不当、术中过度撑开、终板刮除过多、使用非限制性钢板、采用同种异体骨植骨、螺钉进钉深度过浅和方向不当、钢板放置位置偏斜等。术后所有患者JOA评分比术前平均增加3．5分（P〈0．01）。162例未发生钛网下沉患者术后3个月和6个月的JOA评分比术前平均增加4．4分和4．7分：发生钛网下沉患者中。6例有临床症状者沉陷时和沉陷3个月时的JOA评分为2．9分和3．8分．7例无临床表现者为3．3分和3．9分．4例有临床症状行翻修手术者翻修术后1周和3个月时JOA评分比翻修前提高3．3分和3．7分。结论：颈前路钛网植骨融合术后可发生钛网下沉，骨质疏松患者应该避免使用钛网。手术时应尽可能增加钛网与终板接触面积，多保留相邻终板，选用限制性钢板，尽量选择自体骨植骨，避免椎间过度撑开等。防止术后钛网沉陷。     

颈前路钛网植骨融合术后钛网沉陷的原因分析

目的:探讨颈前路钛网植骨融合术后钛网发生沉陷的原因及其对颈椎曲度和临床疗效的影响,并提出相应改善对策。方法:对24例颈前路钛网植骨融合术后钛网发生沉陷的病例行影像学检查,观察骨密度、钛网修剪及放置情况、钢板类型、终板处理情况等,JOA评分法评价手术前后及钛网沉陷后神经功能改变情况,测量手术前后及钛网沉陷后颈椎曲度“D”值并行统计学比较。结果:钛网发生沉陷的原因主要为钛网修剪放置不当、终板刮除过多、术中过度撑开、骨密度下降、选用钢板不适当。术后JOA评分平均增加6.5分(P<0.01),颈椎曲度“D”值平均提高9.25±2.52mm(P<0.05),发生钛网沉陷后18例JOA评分平均增加1.8分,6例平均下降2.1分,“D”值视钛网沉陷发生部位的不同增减不一,但结果均无统计学意义。结论:颈前路钛网植骨融合术后钛网沉陷对颈椎曲度和临床疗效无明显影响;通过合理修剪、放置钛网并使用垫片、椎间适度撑开、保留相邻终板、选用全锁定钢板等措施,可有效防止术后钛网沉陷的发生。     

颈椎前路椎体次全切除钛网植骨早期塌陷的探讨

目的探讨颈椎前路椎体次全切除减压钛网植骨钢板内固定患者钛网应用优缺点.方法57例脊髓型颈椎病患者,病变累及2个间隙49例,3个间隙5例,采用前路椎体次全切除减压钛网植骨并辅以4种不同带锁钢板内固定,其中Orion钢板25例,Zephir钢板11例,Coddman 10例,CSLP钢板11例.对其疗效及钛网融合情况进行评价.结果57例中51例获6～17月随访,植骨均在12周达到临床愈合,3例患者在术后6周发生钛网下沉,颈椎椎间高度降低,颈椎曲度减小,但术后病人主观感觉满意,3月后复查未见进一步下沉.结论钛网植骨比自体髂骨植骨有优越之处,但有发生下沉的可能.正确处理终板、合适的撑开高度、修剪面进行适当处理以及选择全锁定钢板,以降低下沉发生率.     

颈前路椎体次全切钛网植骨早期下沉的探讨

目的：探讨颈椎前路椎体次全切除减压钛网植骨钢板内固定患者钛网早期下沉的原因。方法：30例脊髓型颈椎病患者，病变累及单间隙9例，双间隙17例，3个间隙4例，行前路椎体次全切除减压钛网植骨辅以Orion钢板及Zephir钢板内固定。对其疗效及钛网融合情况进行评估。结果：经术后6个月随访，植骨均在3个月达到临床愈合。4例患者在术后4周发生钛网下沉，颈椎高度降低，颈椎曲度减小，但患者无任何主观症状，3个月后复查见一例患者仍有进一步下沉。结论：钛网植骨比自体骨植骨有优越之处，但有下沉的可能。正确处理终板，合适的撑开高度，正确的钛网截切技术及锁定钢板的选择，可以减少钛网下沉的发生率。     

颈椎前路椎体次全切除钛网植骨早期塌陷的探讨

目的：探讨颈椎前路椎体次全切除减压钛网植骨钢板内固定患者钛网应用优缺点。方法：57例脊髓型颈椎病患者，病变累及2个间隙49例，3个间隙5例，采用前路椎体次全切除减压钛网植骨并辅以4种不同带锁钢板内固定，其中Orion钢板25例，Zephir钢板ll例，Coddman l0例，CSLP钢板ll例。对其疗效及钛网融合情况进行评价。结果：57例中5l例获6-17月随访，植骨均在12周达到临床愈合，3例患者在术后6周发生钛网下沉，颈椎椎间高度降低，颈椎曲度减小，但术后病人主观感觉满意，3月后复查未见进一步下沉。结论：钛网植骨比自体骸骨植骨有优越之处，但有发生下沉的可能。正确处理终板、合适的撑开高度、修剪面进行适当处理以及选择全锁定钢板，以降低下沉发生率。     

颈前路椎体次全切钛网植骨钛网裁切技术探讨

目的探讨颈椎前路椎体次全切除减压钛网植骨钢板内固定患者术中钛网修剪的技巧以获得更好的接触面.方法47例脊髓型颈椎病患者,病变累及单间隙7例,双间隙40例,行前路椎体次全切除减压钛网植骨并辅以O-rion钢板内固定.术中根据钛网结构和所需长度进行设计,采用四种不同的方法进行剪切.结果47例中43例获6～18月随访,植骨均在12周达到临床愈合,未见钛网下沉、颈椎椎间高度及曲度改变.结论通过针对不同长度的特殊设计和钛网剪切,增加钛网接触面积,可以减少因接触面原因导致的钛网下沉.     

颈椎椎体次全切除钛网钢板固定治疗颈椎管狭窄症

目的探讨颈椎椎体次全切除钛网钢板固定治疗颈椎管狭窄症的疗效。方法对确诊为颈椎管狭窄症患者62例,采用颈前路椎体次全切除钛网植骨钢板固定,对比手术前后患者的JOA评分,分析术前、术后及随访时的动力位片,观察钛网、钢板的位置及颈椎前凸角的变化。结果获得完整随访的患者42例,术后随访6～48个月（平均24个月）,6～8个月均获得植骨融合。术后颈椎前凸角改善明显,钛网及钢板位置稳定,JOA评分在术后获得较显著提高（P〈0.05）。结论颈椎椎体次全切除钛网钢板固定治疗颈椎管狭窄症近期疗效肯定,是一种值得推广的术式,但该术式应严格掌握其适应证。     

颈椎椎体次全切除钛网钉板系统的临床应用

目的探讨颈椎前路椎体次全切除钛网钉板植骨融合的临床效果。方法自2001年3月～2003年3月间应用颈前路椎体次全切除钛网植骨融合及钉板固定治疗颈椎管狭窄性疾病22例，其中4例患者行2椎体次全切除3节椎间隙减压手术。术后观察减压、固定、融合及神经功能恢复情况，并行X线摄片或CT扫描检查。结果患者获6～12个月随访，神经功能得到不同程度改善，无加重情况。椎间隙高度无丢失、无成角，均获得骨性融合。术后3d在颈围领固定下下床活动，4周后可恢复较轻工作。结论此术式可避免传统手术方法的缺点，即不取自体髂骨，融合率高，稳定性好，并减压彻底，疗效好，是一种值得推广的新技术。     

新型颈前路翼形钛网三维有限元分析

目的运用三维有限元法分析新型翼形钛网（aliform titanium mesh cage,ATMC）的生物力学性能;评价该内固定的外形设计及生物力学合理性并提出优化指导方案。方法在C4～C6三维有限元模型的基础上,利用Ansys9.0软件前处理器的建模功能建立颈前路椎体次全切减压翼形钛网植骨固定手术模型。对模型施加73.6N轴向压缩载荷及1.8Nm力矩,分析记录前屈、后伸、侧弯及旋转工况下新型翼形钛网内部应力分布及大小情况。结果在后伸、侧弯、旋转工况下,翼板基底部及钉孔周围均出现应力集中现象。应力集中以旋转工况最明显。各工况下笼内植骨块应力总体均匀,大小适宜。结论新型翼形钛网总体外形设计合理,模拟力学安全性能可靠;同时在翼板、翼板基底部存在应力集中现象,需待优化。     

Radiological analysis of titanium mesh cages used after corpectomy in the thoracic and lumbar spine: minimum 3 years' follow-up

This study analyses radiological outcome of titanium mesh cages used for anterior column support following corpectomy in the thoracic and lumbar spine in 34 patients with a minimum three-year follow-up. The aim of the study was to assess the complications and radiological outcomes of patients with structural cages implanted into the anterior column. Titanium mesh cages for the anterior column became popular for anterior column reconstruction following discectomy and corpectomy. Few clinical studies are published assessing their efficacy as a structural graft after corpectomy and factors for the development of settling and correction loss are not investigated enough. Thirty-four patients with minimum 3-year follow-up were analysed radiologically for correction achievement, cage settling and fusion inside the mesh cage. The effect of fixation technique, anatomical localisation and diagnosis for the development of settling were analysed. Measurements of preoperative and early postoperative local kyphotic angle revealed that a mean correction of 27 degrees (range: 8 to 60) was obtained. While no dislodgement or fracture of titanium mesh cages was observed, there was a mean correction loss of 4 degrees and settling (> 2 mm) was noted in 6 patients. Short posterior and only anterior instrumentation systems were associated with settling. The anatomical location and diagnosis did not affect the development of cage settling. Following corpectomy and mesh cage implantation, isolated anterior fixation or short posterior fixation do not provide enough stability, and correction loss and settling can occur.     

自体椎体骨钛网支架融合器在颈椎病治疗中的应用

目的　探讨前路钛网支架自体椎体骨移植替代髂骨进行颈椎前路减压融合治疗脊髓型颈椎病的可行性。方法　采用颈椎前路开槽减压钛网支架自体椎体骨颗粒嵌压植骨结合前路钛钢板固定治疗颈椎病 2 8例。分型 :脊髓型 1 8例 ,神经根型 5例 ,混合型 5例。累及二个椎间隙 2 3例 ,三个椎间隙 5例。在前路减压完成后 ,选择合适长度和直径的钛网支架植入 ,其中加压填充术中所取椎体骨颗粒 ;前路钛钢板固定以获得早期稳定。按JOA评分评定手术效果 ,颈椎正侧位及屈伸位X线检查判定融合效果。结果　JOA评分从术前 (1 2 6 2± 1 5 4 )提高到术后 (1 5 1 2± 1 2 5 )分 ,无一例患者症状加重 ;按照Odom标准评定 ,优良率达 89%。经X线片检查证实椎体间隙高度得到恢复 ,植入物无移位脱落、钛钢板及螺钉无移位及松动 ,植骨融合良好。 1例钢板位置不正 ,1例 2枚螺丝钉进入椎间隙 ,未引起不良并发症。结论　脊髓型颈椎病前路手术中采用钛网包容的自体椎体骨颗粒行植骨融合结合前路钛钢板固定术可替代自体髂骨融合术 ,治疗效果近期是肯定的。可以缩短手术时间 ,避免取髂骨的并发症     

Vertebral autograft used as bone transplant for anterior cervical corpectomy: technical note

OBJECTIVE: In this prospective patient study, we used a surgical technique for autograft bone fusion during anterior cervical corpectomy (ACC) in patients experiencing cervical spondylotic myelopathy. We packed the resected bone material of the corpectomy into a titanium mesh cage. To evaluate the efficacy of our autograft technique, we analyzed the results according to neurological outcome, radiological outcome, and complications. METHODS: Between 1995 and 1998, 27 ACC operations were performed for cervical spondylotic myelopathy caused by multisegmental cervical spondylosis. In all patients, decompression of the cervical canal and/or spinal nerve roots was performed by a median cervical corpectomy by an anterior approach. After the ACC was completed, a titanium mesh cage, which was variable in diameter and length, was filled with morselized and impacted bone material from the cervical corpectomy and was then implanted. An anterior cervical plate was placed in all patients to achieve primary stability of the cervical vertebral column. Age, sex, pre- and postoperative myelopathy, number of decompressed levels, radiological results, and complications were assessed. The severity of myelopathy was graded according to the scoring system of the Japanese Orthopaedic Association. RESULTS: Symptomatic improvement of neurological deficits was achieved in 80% of the patients. The mean preoperative Japanese Orthopaedic Association score improved from 13.1 to 15.2 postoperatively (P < 0.05). No patient demonstrated worsening of myelopathic symptoms. Radiological follow-up studies demonstrated complete bony fusion in all patients. A vertical movement of 2.25 +/- 0.43 mm of the titanium cage into the adjacent vertebral bodies was observed in 24 patients. In patients with either a lordotic or neutral cervical spinal axis postoperatively, the axis remained unchanged during the entire follow-up period. CONCLUSION: The results of this study demonstrate that transplantation of autograft bone material harvested during the ACC integrated well in the cage and in the adjacent vertebral bodies. Thus, complications associated with explantation of autograft material from other donor sites, e.g., the iliac crest, could be avoided. The early postoperative and midterm follow-up periods provided no evidence of morphological or functional instability of the operated cervical segments when this autograft technique was used in combination with cervical instrumentation.     

Efficacy and safety of the use of titanium mesh cages and anterior cervical plates for interbody fusion after anterior cervical corpectomy

BACKGROUND: To determine the safety and effectiveness of the use of titanium mesh cages (TMCs) and anterior cervical plates (ACPs) for interbody fusion after anterior cervical corpectomy. METHODS: From June 2001 to June 2003, 15 patients underwent reconstruction with TMCs and ACPs for interbody fusion after anterior cervical corpectomy in our hospital. The mean follow-up is 13.6 months (range, 9-24 months). Subjects included those with cervical degenerative, traumatic, or pathological diseases. Titanium mesh cages were filled with autologous bone grafts taken from the corpectomy and iliac crest bone chips and were all filled with triosite (calcium phosphate ceramics). The patients' observable signs, neurological reconstruction results, and complications were fully and explicitly recorded throughout the procedure. Radiological imaging studies for measurements of coronal and sagittal angles, sagittal displacements, and settling ratio changes were performed to evaluate spinal stability. We used axial cervical computed tomography (CT) and reconstructive sagittal cervical CT to demonstrate interbody fusion within titanium mesh. RESULTS: The alleviation and frequent disappearance of the subjects' original symptoms and the significant neurological recovery obvious in most patients indicated that postoperative spinal stability could be well maintained. No significant differences in mean cage height-related settling rates, mean sagittal displacements, and mean coronal and sagittal angle changes were observed between 1-level and multilevel corpectomy. All patients who received axial and reconstructive sagittal cervical CT scan could demonstrate true interbody fusion within TMC, and no nonunions were present. Cage malplacement was observed in one subject who had neck pain and neck stiffness, rather than from radiculopathy or myelopathy. One subject died of acute myocardial infarction. There were no ceramic-related complications. CONCLUSIONS: Based on preliminary findings from this study, reconstruction involving TMC interbody fusion with ACP fixation after anterior cervical corpectomy serves as an effective and safe method for the treatment of cervical disease.     

Pitfalls of anterior cervical fusion using titanium mesh and local autograft

Cervical fusion cages have been developed to provide an anterior structural support without harvesting tricortical iliac bone. Limited numbers of investigations have focused on pitfalls of anterior cervical fusion using cage implants. The objective of this study is to report clinical results and implant-related complications in anterior cervical fusion using titanium mesh and anterior plating. Twenty-four cases with anterior cervical fusion using a titanium mesh with local autograft and anterior plating were reviewed. One-level fusion was performed in 7 cases, and 17 patients underwent two-level fusion with corpectomy. The mean follow-up period was 27 months. Radiographic assessment included sagittal alignment, fusion status, and complications related to cage implants. Iliac bone graft harvesting was obviated in all the patients, whereas 15 patients required concomitant use of ceramic bone substitute. Sagittal alignment of the operative level was lordotic in 19 cases (79%) and neutral in 5 cases (21%) at the final follow-up. No late kyphotic collapse was observed. Twenty-three cases (96%) achieved a solid fusion, whereas the time to fusion was averaged 6.2 months. Cage subsidence frequently occurred in 42% of upper vertebrae and 50% of lower vertebrae. The use of titanium mesh and local autograft for anterior cervical fusion obviated the need for harvesting iliac bone block and provided structural anterior column support. However, it required a longer period to achieve a solid fusion when compared with tricortical iliac autograft. Cage subsidence was frequently observed in the early postoperative period.